Internal control for dumb-waiter doors



Oct. 15, 1929. H. PETERSEN 1,731,349

INTERNAL CONTROL FOR DUMB WAITER DOORS Filed June 25. 1928 2 Sheets-Sheet l 1 L Z Z--- w N Y |TW%T0R Halyerfe Zersen BY ATTORNEY WITNESSES Oct. 15, 1929. PETERSEN 1,731,349

INTERNAL CONTROL FOR DUMB WAITER DOORS Filed June 23. 1928 ,7 Sheets-Sheet 2 Q2 o l||||' INVENTOR WITNESSES I? fly 2 f JJgYZyW feiersem.

ATTORNEY MAW Patented Oct. 15, 1929 UNITED STATES HOLGER PETERSEN, OF NEW YORK, N. Y.

INTERNAL CONTROL FOR DUMBJHAITER DOORS Application filed June 23, 1928.

This invention relates to an internal control for dumb-waiter doors.

The primary object of the invention is to provide means to permit the dumb-waiter door of an apartment to be opened only when the dumb-waiter is at the door. In other Words, I provide improved means to prevent the occupants of apartments from opening the dumb-waiter door and throwing articles down the dumb-waiter shaft, or opening the same, or leaving the door open which is a source of great danger in the event of [ire in the basement because, if the door is open, the dumb-waiter shaft will constitute a fine to carry the fire throughout the building, whereas if the doors are kept closed this d nger would be prevented.

A further object is to provide a dumb- Waiter door controlling means carried by the dumb-waiter, which means also functions to close an electric circuit so that the janitor in the basement can ring the bell of the apartment when the elevator is at the door. In other words, my invention provides means whereby the operation of the dumb-Waite].- and the opening and closing of the doors of the different apartments is entirely under the control of the janitor and dangerous and un sanitary conditions, due to the carelessness of the tenants, are thus prevented.

\Vith these and other objects in view, the invention consists in certain novel features of construction and combinations and arrangements of parts, which will be more fully hereinafter described and pointed out in the claims.

In the accompanying drawings Figure 1 is a fragmentary view, in horizontal section, showing my improved construc tion in connection with a dumb-waiter shaft and a door;

Figure 2 is an enlarged view in plan and partly in section of my improved mechanism, showing the door securely latched;

Figure 3 is a view similar to Figure 2, showing the mechanism with door enlarged when the elevator is opposite the door;

Figure 4 is a fragmentar view in section on the line 4-4 of Figure 1;

Serial No. 287,759.

Figure 5 is a fragmentary view in vertical section on the line 55 of Figure 3;

Figure 6 is a fragmentary View in section on the line 66 of Figure 1;

Figure 7 is a View illustrating an electric diagram which may be employed in connection with my improved apparatus.

1 represents the wall of a room, 2 a dumb waiter shaft and 3 a hinged door in the wall 1 communicating with the dumb-waiter shaft 2. 4: represents a dumb-waiter, which may be of any desired construction and mounting, operated in any desired manner to move vertically through the shaft 2 from one floor of a building to another.

It is to be understood of course that all doors communicating with the shaft will have similar operating means, and I shall hereinafter describe one operating mechanism which will apply to all.

The door 3 on its inner face adjacent its free end is provided with an angle bracket 5 that is normally engaged by a spring-pressed latch bolt 6 supported by a bracket 7 secured to the inner face of the wall 1 constituting a part of the elevator shaft.

The latch bolt 6 has a slot 8 therein receiving a crank arm 9 fixed to a short shaft 11. A second crank arm 12 is also fixed to the sha 11, and, in fact, these crank arms 9 and 12 may constitute a single member if desired.

The crank arm 12 has a slot 13 therein receiving a pin 14 on a plunger 15. The plunger 15 is mounted in a bracket 16 secured to the inner face of the elevator shaft 2 at right angles to the latch bolt 6, and a coil spring 17 is mounted on the plunger 15 and exerts a spring pressure in a direction away from the wall 1.

The dumb-waiter 4 is provided with a cam 18 which is movable in the path of the rear end of the plunger 15 so that, when the elevator is moved to a position opposite the door 3, the cam 18 on the elevator will have caused the plunger 15 to move forwardly and close an electric switch 19 in the wall 1 and at the same time cause the latch bolt 6 to be withdrawn, releasing the door 3 so that the latter may be opened.

The door 3 is preferably provided at its ii i) hinged edge with a small pin 20 which operates to close an electric switch 21. This switch 21 is preferably of the push-pin type so that when the pin 20 is forced inwardly it will close the circuit, and when the door is opened a spring or other suitable member will force the pin outwardly and open the circuit.

As illustrated in the electric diagram (Figure 7), the electric switches 19 and 21 are included in circuit with a bell 22 in the apart ment and are also included in circuit with a battery or other source of electricity 23 and with any form of switch or circuit closer 2% in the basement. 7

As indicated in the diagram (Figure 7), the hell or alarm in any or all of'the apartments may be controlled by the single circuit close-r 24 in the basement because the circuits to the bells of the different compartments are only closed when the elevator is at the door of that apartment, and no bell can be sounded until the elevator is at the door and the door is closed.

My improved apparatus therefore does two separate and distinct things: first, it releases the door when the elevator is at the door, and allows the door to he opened only when the elevator is at the door; secondly, when the elevator is at the door the apparatus functions to close the circuit to the bell of that apartment if the door is closed. Hence, the tenants soon realize that if they desire service they must keep the door closed at all times and close it after removing articles from the elevator or placing articlesthereonor otherwise the janitor in the basement cannot ring the bell of the apartment.

iVhile I have illustrated what I believe to be a preferred embodiment of my invention, it is obvious various changes and alterations might be made in the general form of the parts described without departing from my invention and hence I do not limit myself to the precise details set forth but consider myself at liberty to make such changes and alterations as fairly fall within the spirit and scope of the appended claims.

I claim: I

1. The combination with an elevator shaft, a door communicating therewith and an elevator in the shaft, of aspring-pressed la ch inthe shaft normally engaging the door and holding the same in closed position, a springpressed plunger in the shaft, means operatively connecting the plunger and the latch, a cam on the elevator adapted when moved to a position back of the door to cause said plunger to move and release the latch, an alarm, a switch closed by the plunger when moved to release the door, said switch included in an electric circuit with said alarm, and a circuit closer in the basement of the building whereby when the elevator is at a certain floor an operation of the circuit closer by the janitor will ring the alarm in one apartment only.

2. The combination with an elevator shaft, a door communicating therewith and an elevator in the shaft, of a spring-pressed latch in the shaft normally engaging the door and holding the same in closed position, a springpressed plunger in the shaft, means operatively connecting the plunger and the latch, a cam on the elevator adapted when moved to a position back of the door to cause said plunger to move and release the latch, an alarm, a switch closed by the plunger when moved to release the door, said switch included in an electric circuit with said alarm,

a circuit'closer in the basement of the. building whereby when the elevator is at a certain floor an operation of the circuit closer by the janitor will ring the alarm in one apartment only, and a second circuit closer included in the said circuit and closed by the door when the door is closed. 7 V

3. In combination with a building and an elevator in the building movable through an elevator shaft and adapted to communicate with a number of different floors in the building, means in the elevator shaft for normally locking doors communicating with the elevator shaft at the different floors, means on the elevator to release the door-holding means when registering with the door of a particular 

